Snubber



N0v.2,1937. I w. c. HEDGCOCK ET AL ,0 7 5 SNUBBER Filed Nov. 10, 1933 3Sheets-Sheet 1 Invefit'm' William GHeggcocK Nov. 2, 1937. 'w. c.HEDGCOCK El AL 2,097,523 smam Filed. Raw. 10-, 1953 5 Sheets-Shad: 2 v

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Patented Nov. 2, 1937 SNUBBEB 'William C. Hedgcock, Wilmette, and David1!.

light, Evanston, 11L, asaignors, by meme assignments,

to Oardwell-Westinghouse Company, a corporation of Delaware ApplicationNovember 18, 1983, Serial No. 887,888

1; Claims. (01. 201-9) This invention pertains to snubber springs andmore particularly to snubbing spring arrangements adapted for use withrailway car trucks.

It is an object of this invention to provide a spring assembly embodyingshock absorbing and snubbing features.

Another object is to provide snubbing springs which can besubstituted-for existing springs in railway car trucks.

Yet another object is to provide resilient supporting means for the loadcarrying member of a car truck for dampening the movement of said loadcarrying member.

With these and various other objects in view, the invention may consistof certain novel features of construction and operation as will bemorefully described and particularly pointed out in the specification,drawings and claims appended hereto.

In the drawings, which illustrate embodiments of the device and whereinlike reference characters are used to designate like parts Figure 1 is asectional elevation of one form of snubbing spring arrangementembodyingthe invention;

Figure 2 is a top plan view of the snubber arrangement shown in Figure1;

Figure 3 is a sectional elevation of a modified form of snubberarrangement;

Figure 4 is a sectional elevation of another modified form of snubberarrangement;

Figure 5 is a sectional plan view taken substantially in the plane asindicated by the line 5-5 of Figure 4;

Figure 6 is a sectional elevation corresponding to Figure 4 showing thesnubber arrangement in compressed position;

Figure '7 is a sectional elevation of still another modified form ofsnubber;

Figure 8 is a sectional plan view taken substantially in the plane asindicated by the line 8-8 of Figure '7;

Figure 9 is a sectional elevation of a further modified form of snubberarrangement.

Referring first of all more particularly to the snubber arrangementsillustrated in Figures 1 to 3 inclusive, the devices consist essentiallyof a helical spring 28 preferably formed from a square or rectangularsteel bar. Within the spring so formed a friction device 22 is providedincluding a plurality (shown as four) of rectangularly disposedfrictional segments or shoes 24, the outer surfaces of which makecontact. with the inner surface of the spring 28. The segments 24 arenominally of cylindrical shape in their assembly ments 24.

within the helical spring, each segment being provided at each endthereof with the conical wedging surface 28, against which is mountedthe wedging ring 28 having cooperative wedging surfaces 88 engaging thesurfaces M of the scs- 6 ments 24. The two wedging rings 28 are forcedaway from each other by means of the coil spring 22 whereby there is aconstant tendency for the friction segments 24 to expand away from eachother and make a tight contact between their 18 outer friction surfaces84 and the inner surfaces of the spring 28. I I

In the construction illustrated in Figure 3, end plates 86 are providedon the spring 28, being positioned in the spring by means of the flange15 38 and provided with a depressed end portion 48 for accommodating thehead of the bolt 42, the bolt 42 passing through and being looselyconnected to the friction elements or, wedging rings 88. By providingthe bolts 42 the friction ele- 20 ments are kept within the centerportion of the helical spring and the bolts prevent the wedging ringsfrom moving away from the ends of the coil spring to the extent limitedby the length of the bolts whereby the entire assembly is prevented 2from becoming disassembled and the friction device is prevented frommoving to either end of the coil spring.

With these constructions it will be noted that when the helical spring28 is compressed so that 39 the upper surfaces move towards the lowerelements a considerable amount of sliding takes place between the innersurfaces of the helical spring and the outer surfaces of the frictionsegv The amount of energy absorbed by such friction may be varied by thecapacity of the coil spring 82 which constitutes the resilient meanscontrolling the pressure between the friction surfaces 28 and 38 of thefriction members 24 and 28 respectively. By this mechanism the 4.compression of the helical spring 28 is caused to require greater forcethan the resilient reaction of the helical spring 28, and the release ofthis helical spring is further retarded by the same frictional medium.

Referring now to the constructionillustrated in Figures 4 to 6inclusive, the device consists of the helical spring 44 shown as formedfrom a bar of circular section. The spring is provided at each end withthe spring caps 48, said spring caps being provided with frictionelements or shoes 48 extend ng within the helical spring, the frictionelements each having conical shaped or tapered bores 58 against whichsurface friction elements 55 '52 are seated. The friction elements areshown as four in number and are mounted within the bore 50 havingcomplementary friction surfaces 54 cooperating therewith. Each of thefriction elements is provided with the conical friction surfaces 56against which the friction 0r wedging rings 58 are seated, said ringsbeing provided with complementary friction surfaces 60 having frictionalengagement with the surfaces 56, the rings being held tightly againstsaid friction surface by means of the coil spring 62 disposed betweenthe spaced wedging rings. Bolts 64 are seated in the recesses 66provided in the spring caps and are loosely connected to the wedgingrings 58v extending. through a' suitable aperture provided therein, thebolts serving to prevent disassembiy of the entire device and toposition the friction wedging assembly therein, the spring 62 beingpositioned by means of the boss provided on rings 58 through which thebolts pass.

In this construction it will be seen that when the load is applied tothe assembly at the ends, and the helical spring is compressed, thespring caps are caused to travel towards each other thereby causing theconical surface 50 to slide on the complementary surfaces 54 of thefriction elements 52. That is, the friction elements are forced towardeach other causing an inner assembly of smaller diameter to be formed.Such contracting of the assembly of friction elements is resisted by theresiliency of the coil spring 62 and the frictional contact between thesurfaces 56 and 60. The force required to compress the unit depends,first on the resistance offered by coil spring 44; and second, thefriction developed between the outer surfaces 54 of the frictiOnelements .52 and the surface or inner bore ill of the friction elements48 integrally formed on the spring caps 46. This friction in turndepends upon the-force exerted by coil spring 02 and the frictionbetween the surface 60 of conical weds'ing ring 58 and the surface 5! ofthe friction elements 52. When the helical spring assembly is beingcompressed the force must overcome the resiliency of the spring,the'friction between the surfaces 50 and 54 and the friction between thesurfaces 56 and 60. When the force compressing the helical spring 54 isreleased these frictional elements retard the resilient pressure exertedby the spring. Thus a snubbing as well as a shock absorbing springassembly is provided.

Referring now more particularly to the constructions illustrated inFigures 7 to 9 inclusive,

the assemblies also consist of the helical spring 68 preferably made ofa bar of square or rectangular section whereby a substantiallycylindrical surface is provided by the inner bore of the spring. Withinthe spring there are mounted two spaced longitudinally disposed frictionelements or shoes III the outer faces of which are complementary .to theinner surface of'the spring 68. The two friction elements III areprovided with spaced helical spring seats 12 adapted to receive thetransversely disposed coil springs 14 positioned thereon by means of thedowels 16 whereby the friction elements are resiliently forced apartfrom each other and against the inner bore of the helical spring to theextent that pressure is exerted through the compression of thetransverse springs 14 between the elements III.

In the construction illustrated in Figure 9, the elements 10 are shownprovided with the recesses 18 whereby the end lips or flanges Ill areadapted to engage outwardly disposed cooperating flanges 82 on the endcaps 84 whereby the friction elemehts are maintained in a centralposition within the spring assembly. When the helicalspring iscompressed the projection or flange 82 will go downwardly in the recess18 and if the elements 10 also move downwardly through action of itscontact with the bore of the spring 10, then the projection 82 will pullthe friction elements back into their original position when the springassembly is released.

In the constructions illustrated, the spring group may be provided in a.bolster opening or window of a truck side frame to resiliently supportthe bolster transom or other load carrying member disposed therein, theaction of the devices serving to act as a. shock absorber and a snubberfor retarding vertical movements of the load carrying member withrespect to the associated side portion.

Although the devices are shown as spring assemblies, it is of course tobe appreciated that they may be incorporated into the side frames andload carrying members, as for example the spring caps 4i illustratedparticularly in Figures 4to 6. inclusive, may be integrally formed onthe load carrying member and side frames whereby positioning means areformed for the helical springs and friction elements disposed within themembers 48 as already described.

It is to be understood that we do not wish to be limited by the exactembodiments of the device shown, which are merely by way of illustrationand not limitation, as various and other forms of the device will ofcourse be apparent to those skilled in the art without departing fromthe spirit of the invention or the scope of the claims We claim:

1. In a. cushioning device, the combination of a spring having a centralopening, friction shoes disposed in said opening and having slidingcooperation with said spring, said shoes having end wedging portions,wedging members having fric-' tion surfaces contacting said wedgingportions, resilient means interposed between said wedging members urgingsaid members toward said wedging portions, abutment means engaging theends of said spring, and means connected to said abutments and saidwedging members for maintaining said shoes, wedging members andresilient means in position with respect to said spring.

2. In a cushioning device, the combination of a spring formed from a barof substantially rectanguiar section and having a central opening,friction shoes disposed in said opening and having sliding cooperationwith said spring, said shoes having end wedging portions, wedgingmembers having friction surfaces contacting" said wedging portions,resilient means interposed between said wedging members urging saidmembers toward said wedging portions, abutment .means engaging the endsof said spring, and

means connected to said abutments and said wedging members formaintaining said shoes. wedging members and resilient means in positionwith respect to said spring.

3. In a cushioning device, a load supporting helical spring, a cap .ateach end of said helical spring, a plurality of friction shoes engagingthe interior of said spring, said shoes being of a length less than saidspring, each shoe being positioned in the central portion of saidhelical spring and extending toward each end thereof, means forresiliently forcing said shoes laterally into frictional engagement withthe interior of said spring, and rigid means operatively connected withsaid caps for positioning said shoes in both directions relative to saidspring during the ex pansion of said spring after compression. I 4. In acushioning device, a load supporting helical spring, friction surfacesassociated with said spring, a plurality of shoes within said spring forengaging said surfaces, means including springs for forcing said shoesradially outwardly into a substantially constant frictional engagementwith said surfaces, and rigid means for positioning said shoes withinsaid helical spring;

5. In a'cushioning device, a load supportinghelical spring, frictionshoes within said spring,

spring members engaging said shoes and extending transversely of saidhelical spring for forcing said shoes radially outwardly with asubstantially constant pressure into frictional engagement with saidspring, caps for the ends of said spring, and means on said capsengaging said shoes for positioning the same within said spring.

6. In a cushioning device, a load supporting helical spring, means,including a spring member and friction elements within said .helicalspring for frictionally resisting the compression of said spring, saidfrictional resistance being substantially constant, and means forpositioning said first-named means within said helical spring. 7. In. acushioning device, the combination of a load supporting helical springformed from a 7 bar of substantially rectangular section wherebyasubstantially cylindrical bore is provided, friction shoes disposed insaid bore and having arcuate surfaces cooperating over their entirewidth with said-spring, said shoes having end wedging portions, wedgingmembers having tapered friction surfaces contacting said wedgingportions, and a spring interposed between said wedging members urgingsaid memberstoward said wedging portions for forcing said shoes radiallyinto frictional contact with said helical spring at a substantiallyconstant pressure.

8. In a cushioning device, the combination of a load supporting helicalspring wound to provide a cylindrical, bore, shoes of less length thansaidspring. disposed -in said bore and having arcuate surfacesfrictionally engaging said spring throughout their length, each of saidshoes having a wedgingportion on each end thereof, wedging membershaving conical friction surfaces contacting said wedging portions, and aresilient means interposed between said wedging members [urging saidmembers toward said wedging portions.

9. In a cushioning device, the combination of a load supporting helicalspring formed from a bar of substantially rectangular section whereby asubstantially cylindrical bore is provided, friction shoes disposed insaid bore and having arcuate surfaces frictionally engaging said springthroughout their entire length, said shoes having end wedging portions,tapered wedging members having friction surfaces contacting said wedgingportions, a spring interposed between said wedging members urging saidmembers toward said wedging portions with a constant pressure, and

means having cooperative relation with said wedging members formaintaining said shoes, said wedging members and said last named springin a predetermined position with respect to said first named spring.

10. ma cushioning device, the combination of a load supporting springhaving a central cylindrical opening, friction shoes disposed in saidopening and having arcuate surfaces cooperating over their entire widthwith said spring for frictionally resisting the compression of saidspring, each shoe having a wedging portion on each end thereof, wedgingmembers having friction surfaces contacting said wedging portions,resilient means interposed between said wedging members urging saidmembers toward said wedging portions, and means for maintaining saidshoes,

wedging members and resilient means in position between the ends of saidfirst named spring with respect to said spring. 7

11. In a cushioning device, a load supporting helical spring, a cap foreach end of said spring,

rigid means connected to each cap extending into 1 said spring, frictionshoes, said means engaging said shoes for positioning the same withinsaid spring, and means including a spring element for forcing said shoesradially outwardly for frictionally engaging said spring for yieldinglyresisting the compression thereof.

' WILLIAM C. HEDGCOCK.

DAVIDM. HGHT.

